Particularities of licensing of activity related to cryptocurrency in the US are in the federal structure of the United States. Except requirements of the national regulator, nearly each state sets its own requirements. The latter may differ from each other. Consequently, if the crypto exchange intends to provide services on cryptocurrency exchange in several states, its activity will be subject to licensing in each of these states.
For instance, New York state requires to obtain special license called BitLicense to operate activities related to the cryptocurrency exchange.
Nevertheless, yet not all states have finally decided regarding their position in relation to the exchange of cryptocurrencies. In addition, the position of regulators has a tendency to change from time to time.